Field of the Invention
The present invention relates to authentication among ECUs in a vehicle system including a plurality of ECUs.
Description of the Related Art
In recent years, the number of computers (electronic control units (ECUs)) mounted on a vehicle has increased and the ECUs cooperate with each other to perform sophisticated control. Such a vehicle network system may conceivably become a target of attacks such as contamination by illegal data, illicit rewriting of an ECU program, replacement with an illegal ECU, and addition of an illegal ECU.
As a countermeasure against such attacks, the AUTOSAR standard proposes message authentication using a common key. For example, when starting up an engine, a challenge response authentication using a common key is performed and a session key is distributed when the authentication is successful. Subsequently, message authentication with a message authentication code (MAC) using the session key is performed upon message transmission.
In addition, Patent Document 1 below discloses construction of an ad hoc network by mutually valid devices, in which the devices respectively store an ad hoc network ID, an exclusion list specifying specific devices to be excluded from an ad hoc network identified by the ad hoc network ID, and a device certificate generated by a certification authority, and exchange device certificates with each other to check whether the devices are capable of constructing an ad hoc network. In this case, by not performing mutual authentication with devices registered in the exclusion list, the devices registered in the exclusion list are prevented from joining the network.
Patent Document 1: Japanese Patent Application Laid-open No. 2007-074390